论文标题
从星系透镜相差异获得非线性星系偏置约束
Obtaining non-linear galaxy bias constraints from galaxy-lensing phase differences
论文作者
论文摘要
我们证明了用于研究星系偏见的新统计量的实用性和约束功率：星系透镜相位差。统计量包括在弱透镜收敛场和星系计数场之间进行谐波模型的阶段差异。我们使用带有星系的暗物质模拟，直至红移$ z = 1 $来测试该估计器的性能。我们发现相位差异对二阶偏置的绝对值（$ c_2 = b_2/b_1 $）敏感，并证明了为什么是这种情况。对于$ \ sim $ 1500平方英尺。 Galaxy调查我们恢复了$ C_2 $，错误范围为$ C_2 $值的错误约为0.1美元；红移调查的当前限制因红移而定为0.1-0.6。因此，预计这种新的统计量将为$ C_2 $提供约束，这些统计量是互补且具有竞争力的限制功率，而功率谱和Bispectrum的常规估计器则具有约束功率。对于暗能量调查（DES），我们预测二阶偏差的领先测量。
We demonstrate the utility and constraining power of a new statistic for investigating galaxy bias: the galaxy-lensing phase difference. The statistic consists in taking the differences of the phases of the harmonic wave-modes between the weak lensing convergence field and the galaxy count field. We use dark matter simulations populated with galaxies up to redshift $z=1$ to test the performance of this estimator. We find that phase differences are sensitive to the absolute value of the second order bias ($c_2=b_2/b_1$), and demonstrate why this is the case. For a $\sim$1500 sq. deg. galaxy survey we recover $c_2$ with an error of approximately $0.1$ for a wide range of $c_2$ values; current constraints from redshift surveys have errors of 0.1-0.6 depending on redshift. This new statistic is therefore expected to provide constraints for $c_2$ which are complementary and competitive with constraining power by the conventional estimators from the power spectrum and bispectrum. For the Dark Energy Survey (DES), we predict leading measurements of second-order bias.
